Acceleration switch delayed arming fuse



June 23, 1953 I D, H, GLEASQN 2,642,801

AGCELERATION SWITCH DELAYED AMING FUSE Filed June 9, 1947 2 Sheets-Sheet 1 al? q-L 39 56 56 40,l c /f /9 .21.25 42 49 ml o 55 as g2g' H I 'I /2 Il lll l d'9 l [24 Il |`i l Il Il V l* 2'0 5s I /o I YAL/ DANIEL HELE/50N June 23A-@953 n. H. GLEASON 2,642,801

ACCELERATION SWITCH DELAYED ARMING FUSE Filed June 9, 1947 36 48 Ficj. 5.42 J9 2 Sheets-Sheet 2 ,TIL/[pluri LIIIII l ls ,5 /0

gvwonfofb DANIEL H ELEASDN Patented June 23, 1953 ACCELERATIN SWITCH DELAYED ARMING FUSE Daniel H. Gleason, Mountain Lake, N. J., assigner, by mesne assignments, to the United States of America as represented by the Secretary of War Application'J une 9, 1947, Serial No. 753,518

7 Claims.

The invention relates to delayed arming de- Y vices for fuzes, and particularly to means for effecting the arming of a fuse in an ordnance projectile, and for delaying the armingrso that the possibility of detonation is counteracted until the projectile is at a safe distance from the gun from which it is fired.

It is a special aim to perfect such an arming device which Will be particularly applicable to use with electrically actuated fuzes, so as to maintain open circuits throughout the essential electrical elements of the fuze, including a direct main circuit to the detonator as Well as operating circuits responsive to various conditions subsequent to arming. This enables the use ofa `fuze `the electrical action of which may be made responsive to currents or potentials of extremely small value in the order of microamperes or microvolts Without liability oi accidental response by local disturbances, such as static discharges incident to shipment and handling, or by electrical discharges from any source including electric machines, belting, lightning discharges, etc. Y

An object of the invention isthe embodiment of a novel structure in the arming mechanism.

A further aim is the presentation of a'novel delay for a setback release device for an arming mechanism.

An aim is to oder novel means for delaying the arming after actuation oi the setback release.

A still further purpose is to devise a novel switch and interrupter.

It is also sought to provide in an electrically actuated fuze a safety switch of the inertia type utilizing a hydraulic dashpot operable on setback forces resulting from sustained acceleration above a predetermined value to release a rotatable means for closing the electrical contacts of the fuze.

Additional objects, advantages and features of invention reside in the construction arrangement and combination of parts involved in the embodiment of the invention as Will appear or be understood from the following description and accompanying drawings, wherein:

Figure 1 is an elevation of the arming unit for a fuse removed from the fuse and without wiring; this is about double'the actual size of the machine as heretofore built;

Figure 2 is a tcp view of said unit, in un- Figure 4 is `a view on the line 'I-l of Figure 5 'showing themultiple switch in unarmed posi- Figure 5 is a View similar to Figure 2 showing the device in armed condition;

Figure 6 is a View similar to Figure 3 showing the device in armed condition;

Figure 7 is a View similar to Figure 4 showing the armed condition;

Figure 8 is a perspective of the rotor body;

Figure 9 is a diagram of a detonator circuit and control circuits and the switches, as an example;

Figure 10 is a top view of the governor with the cap case thereof removed.

Referring more particularly to the drawings, there is illustrated an arming unit which is intended to be set in the fuze cavity of a projectile and in the present instance associated with an electrically actuated fuze which will have an electrical source included therein. The arming assembly includes a base I IJ of circular form adapted to be die-cast over which there is xed a parallel frame plate II occupying approximately a semi-circle aligned with the base plate. A detonator holder I2, is xed'on the upper side of the plate II, and in line with this there are flash ports I3 and I4 in the plate il and base ID respectively. An interrupter disc I5 is revolubly mounted between the base` I0 and plate II, and in this disc there is formed a flash port I6 which isA aligned with those first'mentioned when the disc is in armed position. The interrupter has a coaxial shaft pivoted in the base It, extended through and above the plate Il, carrying at its upper end a iianged collar I7 having a number of small peripheral notches I' slightly inclined counterclockwise toward their open ends as viewed from above. A helical torsion spring IE around the shaft has one end anchored to the plate II, and its upper end formed with a hook vwhich is selectively engaged in one of the notches S under tension tending to drive or rotate the interrupter in a clockwise direction as viewed in Figures 2 and 5.

Means to be described is provided to hold the interrupter releasably in a position rotated counterclockwise to an unarmed or safe position with the port I8v spaced a distance from the other flash ports mentioned. Through a speed multiplying gear train 20 a centrifugal governor 2| is connected to the interrupter, which has an integral gear portion thereon to drive the train. rlhe governor rotor 22 is mounted on the shaft 23 of the last gear 24 of the train. This shaft is mounted in the base I 0, plate I I and an inverted cap-like cylindrical case 25 tted around a lip or flange `26 at the edge ofan opening through the plate AVII concentric with the shaft 23. The

governor rotor comprises an arm 21 arranged diametrically inthe case 25 and has a clutch hub 23 revoluble around the shaft 23, with a conventional clutch 'device therein or thereon to engage between the rotor andV shaft under rotation of the shaft by the gear train, but to release the rotor or at least permit it to rotate in the same direction without dire shock to the shaft 23 when the latter stops abruptly.

The clutch comprises two semicircular shoes 29 (which also constitute the weights of the governor) pivoted on the respective ends of the arm 21 and a bracket 3U fixed on the arm carrying two leaf springs 3l bearingon the inner sides of projecting short heel arms 32 of the shoes so that the longer arms 33 of the shoes are held yield- Y ingly clear of the cylindrical wall of the case 25. The opposed ends of the shoes are cut diagonally so that the short arm of one shoe'serves as a stop for the lapped long arm of the other. The bracket 33 may be rotatively adjustable on the rotor arm so as to regulate the effectiveness of the springs 3l, being secured at adjusted position by a fillister screw 34 engaged through the bracket and in the arm.

Erected upon the base I0 beside the plate II and near the governor 2l there is a dashpot 35 comprising a cylinder vertical to the base and closed integrally at its lower end. Its upper end is sealed by a cap 3B screwed thereon with a gasket interposed againstthe upper end of the cylinder. Slidable in the cylinder is a vented dasher 37, confining in the lower end of the cylinder a protractile spring 38 which initially holds the dasher at'the upper end of the cylinder. The cylinder is filled with a liquid of suitable viscosity and anti-freeze quality. Since the plunger 3T is held at an initial high position in the cylinder against the cap 36 by the spring 33 (yieldable to set-back forces in the plunger by its inertia when the projectile carrying the fuse is fired from a gun), the liquid is practically all below the dasher.

A substantially U-shaped rotor assembly bracket 39 is mounted at its bight on the base Il), with a switch rotor 40 mounted between its arms, rotatable in a plane bisecting the cylinder 35 longitudinally. By means of atorsion spring4l coengaged between the outer arm of the bracket 39 and the switch rotor, the latter tends to rotate in a counter-clockwise direction as viewed in Figures 1,13, 4', 6, and 7.

The switch rotor includes a concentric metal disc 42, in a diametrical plane of the cylinder, and at a required initial position of the rotor, a notch 43 formed in this disc, receives the bill of a latch lever 44 pivoted on the base IIJ between the switch rotor and the cylinder. The lever is urged toward the cylinder by a torsion spring 45 at its base, but the'upper end of the latch bears against a latch release pin 4B set slidablyr and radially in the wall of the cylinder in said diametrical plane, and at a distance from the cap slightly less than the length of the dasher, so that the pin bears against the dasher, which prevents latch release movement of the pin. This pin is enclosed at its outer part by'a collapsible envelope 41 connected to a suitable guiding nipple on the side of the cylinder, so as to prevent escape of liquid from the cylinder. VThe vent aperture 48 formed through the dasher head is proportioned so as to regulate the time required for complete set-back movement of the dasher under acceleration of the contemplated projectile when red with predetermined ballistic affects.

The inner side of the U-shaped bracket in which the switch rotor is mounted comprises a diagonal arm 49 in which a trunnion of the rotor is revoluble. This arm affords a space in which may move a lateral pin 5i) set in the rotor which clears the arm at the limits of rotation of the rotor. (Figure 3), this pin 50 serves as a detent for the interrupter I5, which has an upstanding post or crank '5I thereon, so positioned that with the interrupter in initial or unarmed position and with the detent pin 5U at its lower or initial position as in Figure 3, the latch 44 will be engaged with the notch 43, and the crank 5I will be held by Vpin 50 in initial position against action of the interrupter driving spring I9.

The switch rotor also carries a disc 52 of insulating material on which movable switch contacts 53 are mounted, and on the outer arm of the bracket 39, which is a plate enlarged for the purpose, there are mounted insulated stationary spring blade contacts 54. The number and relation ofthe movable and stationary contacts, and the leads thereto may be variously organized with the circuits of the electrical elements of the fuze, the details of which are not shown except as formally outlined as an example, in Figure 9, where the switch rotor and its movable contacts are indicated by the general reference character 40 as in the preceding description. The uses of the specific circuits and the reasons for the order of contacts indicated will be understood by those Yversed in the electrical details 0f such switches.

It is suiilcient to say that as shown in Figure 4, the upper two stationary contacts may be considered to be bridged by the rotor contact, and might be a iilament circuit. At the second position of the switch the circuits may be so arranged that the filament circuit would still be closed, and in addition a grid circuit, and a detonating circuit closed, as diagrammatically indicated in Figure 9, although closing of a grid circuit by such switchmay be eliminated, as discretion dictates.

It should be noted that at the armed `position of the interrupter (whereat the ash port I6 is aligned with the ports I3 and I4), the crankv5| is stopped against a stop plate 55, which may be of insulatingmaterial, mounted on an upstanding bracket plate on the frame plate II. sulating plate carries also two depending insulated spring blade contacts 56 stopping close to the interrupter, and on the interrupter there is mounted an insulated movable swit-ch contact 51 which engages and bridges these two spring contacts shortly before the crank 5I engages the plate 55 and stops the interrupter. The contacts 56 may be connected in series in the detonation circuit of the fuze so that until the contact 51 engages, the detonation circuit is open here. Other series connected means forconventionally and additionally completing the detonation circuit elsewhere may be incorporated in the fuze of which my invention may form a part. The specific circuits and additional circuit closing means Vform no novel part of the present invention, and are not shown.

In practice a top plate, not shown, is mounted over the unit represented, on which plugs or prongs maybe set in a standard pattern for insertion in receptacles of a battery unit and for a particular electrical unit chosen for the partcular use to which the fuse is to be put, and conventional leads are extended from these prongs to the stationary contacts of the instant showing, or as modified according to the nature of the At the initial or set position of the rotor f circuits to be controlled. -Such plate may be carried by several upstanding posts 59 set on the base at convenient locations, and serving in part to also support the frame plate H as found expedient. Y

In use, the parts being set in initial positions as shown in Figures 2, 3, and 4, when the projectile equipped with the invention is fired, acceleration offthe projectile in the gun causes the inertia of the dasher to displace liquid from behind it moving the liquid to the forward end of the cylinder through the vent aperture 48. As the dasher reaches a rearward part of its movement near its extreme limit, it clears the end of the latch release pin 4G, allowing the latter to be thrust inward by the latch 44. This will occur as the projectile is in the last part of its acceleration in the gun. This frees the switch rotor 4|] which is otherwise uninhibited and the rotor immediately moves to its closed circuits position of Figures 5 and 7. This places the fuze in a condition Where, except for the open circuit at the contacts 54, the electrical and other elements of the switch may function, according to the nature of the system. This movement of the switch rotor also moves the interrupter detent pin 50 out of the path of the crank 5l and permits initiation of movement of the interrupter to armed position. Such movement may be completely :blocked momentarily if setback forces are excessive, as will be explained, but otherwise is retarded according to the adjustment of the springs 3l, centrifugal force throwing the shoes 29 outward against the wall of the cap case 3B to act as a retarding brake.

The complete movement may require from M1 second, more or less, the latter delay involving a` travel of the projectile of in the neighborhood of '700 feet from the muzzle of the gun before the circuit is closed at contacts 54. Even after this closure, the detonation may be dependent on further action in whatever electrical device or other time delay means there may be incorporated in the fuze in addition to my unit, as before indicated.

In the operation described, when the interrupter reaches its armed position abruptly stopped by the crank 5I, due to the function of the clutch 28, the shock of stoppage will include only the effect produced by stoppage of the interrupter and gear train, and not stresses due to the inertia of the rotating governor parts, which are freed sufficiently to permit them to continue rotative movement with moderate friction on the shaft 23'.

It should also be noted that there is a very small clearance between the periphery of the interrupter and the top surface of the base l0, and

Vwhich it is red.

While the disclosure herein presents my invention in its best embodiment as perfected by me, it will nevertheless be 4understood that it is purely exemplary, and that changes in construction, arrangement and combination of parts may be made within the scope of the appended claims without departing from the spirit of the invention which I have offered.

I claim:

1. In'an arming device for fuzes, an interrupter having an unarmed position and an armed position, means tending to move the same to armed position, a governor operatively connected with the interrupter to control the time of movement from the rst named position to the one second named, said connection between the governor and interrupter comprising a one-way clutch constructed to permit limited free movement of the governor on stoppage of the interrupter, means to hold the interrupter at said unarmed position responsive to inertia forces incident to acceleration of the fuze when propelled from a gun, and means to retard response of the means next last named to a time corresponding to the time of the fuze in the gun.

2. In an electrically operated projectile fuze having spaced flash ports, an interrupter disc including a ash port interposed therebetween having va first unaligned position and a second aligned position, latch means normally holding said interrupter disc at said rst position, biasing means tending to move said interrupter disc from said first position to said second position, hydraulic retarding means comprising a dash pot normally preventing release of said latch means and operative only in response to sustained acceleration to release said latch means after a predetermined time, and centrifugally actuated retarding means operatively connected to and driven by said interrupter disc to retard movement thereof from said rst position to said second position.

3. The apparatus according to claim 2 wherein said centrifugally actuated retarding means comprises a governor.

4. In an electrically operated projectile fuze having spaced flash ports, an interrupter disc comprising a flash port interposed therebetween, said interrupter disc having a rst unaligned position and a second aligned position, latch means normally holding said interrupter disc at said first position, biasing means tending to move said interrupter disc from said rst position to said second position, automatically self-restoring hydraulic retarding means comprising a dash pot normally preventing release of said latch means and operative only in response to sustained acceleration to release said latch means after a predetermined time, and centrifugally actuated retarding means operatively connected to and driven by said interrupter disc to retard movement thereof from said rst position to said second position.

5. The apparatus according to claim 4 wherein said automatically self-restoring hydraulic retarding means further comprises a spring urging said dash pot in the direction of its normal position.

6. In arming device for an electrically operated fuze having spaced flash ports, an interrupter disc comprising a llash port interposed therebetween having a first unaligned position and a second aligned position, normally open electric contacts in said device, electric contact means on said interrupter disc for closing said normally open contacts with said interrupter disc in said second aligned position, latch means normally holding said interrupter disc at said first unaligned position, biasing means tending to move said interrupter disc from said rst position to said second position, hydraulic retarding means comprising a dash pot normally preventing release of said latch means and operative only in response to sustained acceleration to release said g0vernor;said latch ,means -haying normally-'open electric contacts closed upon release thereof by said hydraulic retarding means. Y Y DANIEL H. GLEASON.

References Cited in thele of this patent p UNITED STATESPATENTS Number Name yDate 527,250 Smith Oct.,9, 1894 1,623,475 Hammond, J r Apr. 5, 1927 '2,486,362 OBrien Oct. 25, 1949 FOREIGN PATENTS Number Country Date Italy Nov. 18, 1932 

